Considering a move from NEX-7 to 6D, care to comment on my rationale?

Is that the lenses that Sony offers for it can't handle the 24mp sensor. The NEX 6 with its 16mp sensor is the most these consumer lens can handle. Plus, there isn't a great variety of lenses to choose from. The NEX cameras use an APS sensor not unlike those found in Nikon's crop cameras. They're good sensors, but held back by the lenses.

By moving up to the 6D you'll not only be moving up to a full frame camera, but also one with a wide inventory of lenses to choose from.